Fig 1.
Symptoms observed in Nicotiana benthamiana plants agroinfiltrated with clones of Grapevine Pinot gris virus.
N. benthamiana plants infected with the virulent (pRI::GPGV-vir, A) and latent (pRI::GPGV-lat; B) clones of GPGV showing systemic mottling and chlorosis 2 weeks post inoculum; C) asymptomatic N. benthamiana inoculated with empty vector (mock).
Fig 2.
Symptoms observed in Vitis vinifera plants agrodrenched with clones of Grapevine Pinot gris virus observed 4 months post inoculum.
A) and B) chlorotic mottling developed on emerging leaves; C) short internode (arrow) displays zigzag growth; D) and E) V. vinifera agrodrenched with the latent strain of GPGV showing recovered, lateral branches 5 months post inoculum; F) asymptomatic V. vinifera, agrodrenched with empty vector (mock).
Fig 3.
Representative TEM micrographs of leaf tissue from agroinoculated plants.
Filamentous flexuous virus-like particles are detected in leaf bundle sheath cells of agroinfiltrated N. benthamiana (A, B, C) and agrodrenched V. vinifera (D, E, F). In the bundle sheath cells, membrane-bound organelles (arrow) are observed in both N. benthamiana (B, C) and V. vinifera (D, E, F) agroinoculated plants. In agrodrenched V. vinifera, large globular vesicles and filamentous virus-like particles can be clearly detected inside the membrane-bound organelles (D, E, F, arrows). (BSC: bundle sheath cell, V: virus-like particles).
Fig 4.
TEM micrographs from leaf tissues of mock-infiltrated plants.
Parenchyma cells are well preserved and contain normal-shaped organelles in the leaf tissues of both in N. benthamiana (A, B) and V. vinifera (C, D). (ch: chloroplast, er: endoplasmic reticulum, m: mitochondrion, n: nucleus, va: vacuole).
Fig 5.
Viral titre in infected tissues of N. benthamiana agroinoculated plants (A) and agrodrenched V. vinifera (B) evaluated 4 months post inoculum. In both species, plants inoculated with the latent GPGV clone show a significantly higher ΔCq value, corresponding to a lower virus titre.
Fig 6.
Representative TEM micrographs of immunogold-labelled agroinoculated plants.
In samples incubated with a 1:10 dilution of primary rabbit polyclonal antibody (Pab) against GPGV-coat protein and a 1:50 dilution of secondary gold-conjugated antibody, gold (arrows) is visible in the bundle sheath cells of agroinoculated plants in association with the filamentous particles and in their proximity (A, B). In inset (i), area of interest of A is magnified. Label does not occur in infected samples incubated with buffer alone (C). (V; virus).
Table 1.
List of DNA primers used in this study.